<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>记录时间</title>

    <style>
        div{
            width: 100px;
            height: 100px;
            /* border: brown 1px solid; */
            position: relative;
        }
body{
    background-color: cornflowerblue;
}

        .under{
            background-color: cornflowerblue;
            text-align: center;
            line-height: 100px;
            margin: auto;
            margin-top: 200px;
            /* border: black px solid; */
            animation: overthrow 2S infinite;
            /* box-shadow: black -10px -10px 10px; */
        }
        /* .above{
            text-align: center;
            line-height: 100px;
            z-index: 100;
            margin:auto;
            top: -102px;
            height: 50px;
            background-color: yellow;
            box-shadow: black 1px 1px 1px;
        } */

        @keyframes overthrow{
            0%{
                top : 0;
                left: 0;
                box-shadow: 10px 10px 10px;
            }
            100%{
                top:-10px;
                left: -10px; 
                box-shadow: -60px 20px 20px;
            }
        }

    </style>
</head>
<body>
    <div class="under">
        time
    </div>

    <div class="above">
        time
    </div>
</body>
</html>